Rotors for blowers and fans must be balanced as a rule for practical use in order to guarantee a quiet, oscillation-free operation. For that reason balancing weights are primarily positioned on the outer periphery. The prior art describes several possibilities to do that.
Document DE 10 2009 007 803 A1 describes, in the case of a multi-blade centrifugal fan, a compensating weight with a clamp shape for insertion on an edge area of the fan. This design of a balancing weight has the disadvantage with greatly imbalanced rotors that several weights must be placed next to each other because of the relatively small weight of the individual clamp or clasp. That makes the balancing operation complicated.
DE 10 2010 011 526 A1 also describes a clamp-like balancing weight for a radial fanwheel arrangement which is associated with the same disadvantages as previously described. In addition the fanwheel here has a special design with pocket-shaped recesses in whose regions at least one balancing weight can be mounted.
Another document DE 10 2006 057 087 B3 describes a rotor for a blower, wherein the rotor features special pockets for the insertion of balancing weights.